Google announced what was most likely a Panda data refresh, saying that it could take months to fully roll out. The search filter meant to stop sites with poor quality content from working their way into Google's top search results.

After many reports of large-scale ranking changes, originally titled as Phantom update, Google acknowledged a core algorithm change impacting quality signals. This update seems to have had a broad impact, but Google didn't reveal any specifics about the nature of the signals involved.

More than two years after the original DMCA/Pirate update, Google launched another update to combat software and digital media piracy. This update was highly targeted, causing dramatic drops in ranking to a relatively small group of sites.

Google announced a significant Panda update, which included an algorithmic component. They estimated the impact at 3-5% of queries affected. The search filter is designed to penalize thin or poor content from ranking well.

Google confirmed a major Panda update that likely included both an algorithm update and a data refresh. Officially, about 7.5% of English-language queries were affected. The search filter meant to stop sites with poor quality content from working their way into Google'€™s top search results. Just prior to Panda 4.0, Google updated it's payday loan algorithm, which targets especially spammy queries. The exact date of the roll-out was unclear.

Google confirmed a Panda update, but it was unclear whether this was one of the 10-day rolling updates or something new. The implication was that this was algorithmic and may have softened some previous Panda penalties.

Google announced a targeted algorithm update to take on niches with notoriously spammy results, specifically mentioning payday loans and porn. The update was announced on June 11th, but Matt Cutts suggested it would roll out over a 1-2 month period.

Google started rolling out the next generation of the Penguin webspam algorithm. This is the fourth Penguin-related launch Google has done, but because this is an updated algorithm (not just a data refresh), Google refers to this change as Penguin 2.0.

Right before the Christmas holiday, Google rolled out another Panda update. They officially called it a data refresh, impacting 1.3% of English queries. This was a slightly higher impact than Pandas #21 and #22.

Google announced a change in the way it was handling exact-match domains (EMDs). This led to large-scale devaluation, reducing the presence of EMDs on the search engine result pages. Official word is that this change impacted 0.6% of queries (by volume). Overlapping the EMD update, Google pushed out a fairly major update to the its Panda algorithm affecting 2.4% of queries.

Google rolled out yet another Panda data refresh, claiming that less than 1% of queries were affect. Ranking fluctuation data suggested that the impact was substantially higher than previous Panda data refreshes.

Google rolled out its first targeted data refresh after the initial Penguin algorithm update. This confirmed that Penguin data was being processed outside of the main search index, much like Panda data.

Google launched the Penguin Update that was designed to punish pages that have been spamming Google. Plus Google quietly rolled out a Panda data update. A mix of changes made the impact difficult to measure, but this appears to have been a fairly routine update with minimal impact.

Google announced that an algorithm change rewarding freshness would impact up to 35% of queries (almost 3X the publicly stated impact of Panda 1.0). This update primarily affected time-sensitive results, but signaled a much stronger focus on recent content.

After experimenting for a while, Google officially rolled out expanded site-links, most often for brand queries. At first, these were 12-packs, but Google appeared to limit the expanded site-links to 6 shortly after the roll-out.

Google'€™s Panda Update is a search filter meant to stop sites with poor quality content from working their way into Google'€™s top search results. Google rolled out the Panda Update internationally, both for English-language queries globally and non-English queries except for Chinese, Japanese, and Korean.

The May Day Update is a collective name for a number of permanent and world-wide changes to Google's ranking algorithms between April 28, 2010 and May 03, 2010.
This update had huge implications for so called long-tail keywords. Short-head keywords were mostly spared.
According to Google, these algorithm changes had the goal of keeping the quality of the searchresults.